1. Field
Embodiments of the present disclosure generally relate to nanoparticles for controlled drug delivery and methods of using the same.
2. Description of the Related Art
Obesity is a medical condition in which excess body fat has accumulated to an extent that it may have a negative effect on health, leading to reduced life expectancy and/or increased health problems. In Western countries, people are considered obese when their body mass index (BMI), a measurement obtained by dividing a person's weight by the square of the person's height, exceeds 30 kg/m2, with the range 25-30 kg/m2 defined as overweight. Obesity increases the likelihood of various diseases, particularly heart disease, type 2 diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis. Obesity is most commonly caused by a combination of excessive calorie intake, lack of physical activity, and genetic susceptibility to obesity, although a few cases are caused primarily by genes, endocrine disorders, medications, or psychiatric illness.
Dieting and exercise are the primary treatments for obesity. Diet quality can be improved by reducing the consumption of energy-dense foods, such as those high in fat and sugars, and by increasing the intake of dietary fiber. With a suitable diet, anti-obesity drugs may be taken to reduce appetite or decrease fat absorption. However, diet and exercise may be insufficient to achieve a desired BMI, with preexisting metabolic conditions and patient non-compliance being the primary reasons for failure. In some cases, medical intervention may be appropriate. Medical intervention can include a gastric balloon, a gastric band, or surgery may be performed to reduce stomach volume and/or bowel length, leading to feeling full earlier and a reduced ability to absorb nutrients from food. However, medical interventions can fail for similar reasons as described above. As well, medical interventions carry the inherent risks of adverse events related to all surgeries, such as sepsis or necrosis of the affected regions.
Non-invasive approaches have also been considered. Specifically, pharmacological approaches to anti-obesity (e.g., anti-obesity drugs) carry promise for future treatment. Drugs, such as capsaicin, have been shown to increase metabolism and reduce obesity in mouse models. As is the case with many drugs, capsaicin requires relatively large and sustained doses to achieve the anti-obesity effect. Further, capsaicin is not known to localize to a specific region or cell type, thus increasing the quantity of the drug needed to achieve the anti-obesity effect. The mechanism by which capsaicin prevents weight gain was unknown, further complicating localization. Finally, the prolonged use of pure capsaicin has a variety of side effects, which may limit patient compliance including gastrointestinal discomfort, esophageal irritation, and others related to the burning sensation created by capsaicin. There is currently no therapeutic drug available to decrease abnormal body weight gain.
Accordingly, what is needed in the art is an anti-obesity formulation which can be targeted to specific tissue regions and deliver a sustained release.